The present invention relates to methods and compounds for use with an instrument for performing chemical assays and measurements and, more particularly, to methods and compounds for chemiluminescence-based tests on an instrument employed in performing chemical assays, such as those performing quantitative and qualitative tests on chemical and biochemical solutions.
A variety of assay methods and compounds are employed in quantitative and qualitative analyses of chemical and biochemical mixtures. In some instances, those quantitative and qualitative analyses are performed by an instrument. Certain of the methods and compounds employed in analyses can be useful in testing the instrument employed in those analyses. Such tests may concern, for example, transfer efficiencies, instrument calibrations, membrane pore size measurements, and the like. A number of methods and compounds employed in these tests regarding instruments are known. New methods and compounds and improvements in existing methods and compounds, however, are being developed.
One chemical property utilized in certain analytical applications, including tests regarding instruments is referred to as "chemiluminescence". Chemiluminescence is the emission of light as the result of a chemical reaction. Chemiluminescence occurs when products of a chemical reaction are excited and emit light.
In an exemplary chemical reaction that generates chemiluminescence, a step of the reaction is a chemiexcitation step (which may be unimolecular or bimolecular) which achieves conversion of chemical energy into electronic excitation energy. In the reaction, a product molecule receives chemical energy and converts it to an excited electronic state. This electronically excited product molecule then produces light or luminesces under reaction conditions.
Attempts have been made to automate chemiluminescence measurements. Some attempts have involved a variety of instruments, such as, for example, the use of photographic film and a densitometer to record a chemiluminescent signal from a reaction in clear microtitration plates.
To provide accurate and desired results, measurements and other determinations regarding the systems may be made periodically. These determinations may indicate the condition of the system involved.
For instance, chemiluminescence may be useful in measuring transfer efficiencies and/or other aspects of instruments employed to perform assays which are measured or observed by chemiluminescent characteristics. Instruments which are capable of conforming to minute tolerances in these regards have relatively high transfer efficiencies. Instruments that do not yield accurate component measurements on transfer have relatively low transfer efficiencies. To perform accurate tests with some analytical instruments, knowledge of transfer efficiencies (and, thus, the inherent accuracies and inaccuracies of the instruments) is desirable.
It is known to make certain tests on instruments used to perform assays and other tests for determining the accuracy and the like of the instrument. A known method for making such tests performs particular assays on a standard sample of known composition and characteristics. Because the composition and characteristics of the standard sample are known, results of assays and tests performed with the sample should yield expected results if the instrument were to perform accurately. If expected results were not obtained, inaccuracies of the instrument being utilized may be indicated.
It is known to perform particular tests on the instrument used. In so testing instruments, acridinium activated particles may be used as a standard sample. Acridinium, when reacted with alkaline peroxides, yields a light producing reaction. Some currently available acridinium activated particles used in testing chemiluminescence-based instruments have certain disadvantages. One such disadvantage involves the method of preparing these particles. In this prior method, latex particles are coated with anti-HBsAg labelled acridinium using passive adsorption. Then, activated acridinium is passively adsorbed onto the particle surfaces.
The product activated acridinium microparticles obtained from some prior methods may be disadvantageous for use in testing some chemiluminescence-based instruments. The light emission profiles of particles may not be sufficiently identical to or closely resemble the actual light emission profiles of chemiluminescence-based immunoassays. It is desirable that a standard sample for testing perform substantially the same as an unknown will perform when tested. However, this may not always be the case. A possible reason for differences in light emission of some currently available product activated acridinium microparticles may be stearic hindrance effects caused by acridinium loading.